<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>元素显示模式</title>
    <style>
        div{
            width: 100px;
            height: 100px;
            border: 5px solid #f00;
            display: block;
        }
        span{
            width: 200px;
            height: 200px;
            background-color: #ff0;
            display: inline;
            display: block;
        }
        /*输入框与按钮是行内元素，即可以设置宽高，又横着排*/
        input,button{
            width: 200px;
            height: 200px;
            display: inline-block;
        }
        .d2{
            /*让元素消失 不占据页面的布局空间*/
            display: none;
        }
    </style>
</head>
<body>
<div class="d1"></div>
<div class="d2"></div>
<div class="d3"></div>
<hr>
<span>123456</span>
<span>123456</span>
<span>123456</span>
<hr>
<input type="text">
<input type="text">
<input type="text">
<button>按钮</button>
</body>
</html>